1. Field of the Invention
The subject matter of the invention is a water cooling means for insertable component parts groups in devices of power electronics based on the principle wherein the stray heat from the component parts flows off directly into the cooling water via a layer of metal having good thermal conductivity fashioned as a carrier element required for separating the component parts from the cooling water flowing through the cooling member.
2. Description of the Prior Art
An air-water heat exchanger system is nearly indispensible in all devices in which greater heat quantities are to be dissipated. Given a favorable price, water as the cooling agent has a relatively constant, low temperature and is usually unproblematically available. These facts as well as the high thermal value lead to a very high efficiency given low mechanical outlay, whereby the heat exchanger system can be operated nearly maintenance free.
Water-cooled units in devices of power electronics are constructed upon employment of commercially available elements usually manufactured of aluminum extruded sections which are preferably connected to the cooling water circulation by means of flexible pressure tubing. These comprise water-floodable channels or chambers as well as a preferably planarily designed outside surface particularly carrying the electrical component parts having high stray heat.
Greater numbers of such units, preferably with parallel connection of the electrical component parts groups are arranged in large devices, for example computer tomographs, nuclear magnetic resonance tomographs, etc. A unique problem which shall be disclosed below derives given such devices. The reliability of the devices is of great significance for the operation of such installations. As a consequence of the costs of acquisition, only one such device is usually present. An outage of the system thus means an interruption or cessation of all diagnostics for some time. Since diagnosis departments having such apparatus have waiting lists, a complete re-scheduling of the planned examinations is required, so that, for example, ambulatory patients cannot be examined must be called in again. When the system is down, the fault locating must lead to a successful conclusion as quickly as possible. It is obvious and known to utilize computers as auxiliary means for this purpose. Errors which have occurred can be automatically registered so that the service technician can quickly identify the cause. A prerequisite for quick fault elimination is realized by the employment of assemblies that can be interchanged in case of disruption and by good accessibility. The time required for repair could thus be reduced to a minimum. However, a significant complication and delay occurs due to the water cooling means. In order to replace a malfunctioning assembly, namely, the cooling water connection must be dismantled after the cooling water has been drained out. The risk of damage to the devices due to flow-out of residual water thereby always exists. After a new assembly has been integrated, the cooling water connection thereof must be carefully restored and the cooling water must be re-introduced.